Damper.



N0. 777,330. PATENTED DEG. 13, 1904l M. J. GARRIGAN.

DAMPEB..

APPLIUATIDN FILED JUNE 8. 1903. RENBWED NOV. l0 1904.

N0 MODEL. SHEL'l'SwHBBT` 1.

2 SHEETS--BHBET 2. G Z4 .AU 0 9 l .3 l Uw E D D E T N E T A D..

.7K/,Waff

M. I. CARRIGAN. DAMPER.

APPLICATION FILED JUNE s. 1903. RBNEWBD Nov. 10, 1904.

No MODEL.

Patented December 13, 1904:.

PATENT OEEICE.

MICHAEL JQ CARRIGAN, 0F GLENNS FERRY, IDAHO.

DAMER.

SECFICATION forming part of Letters Patent No. 777,330, dated December13, 1904.

Application tiled June 8, 1903. Renewed November 10,I 1904;. Serial No,232,253. (No model.)

To all whom, t may concern.'

Be it known that I, MICHAEL J. CARRIGAN, a citizen of the United States,residing at Glenns Ferry, in the county of Elmore and State of Idaho,have invented a new and useful Damper, of which the following is aspecification.

This invention relates to dampers designed especially for use in the{ire-boxes of locomotives.

The object of the invention is to provide an improved form of damperwhereby the feed of air to the iire-box may be controlled by the firemanin a simple and effective manner and by which the air supplied to thelirebox will be so directed as to facilitate the consumption of thesmoke and the production of complete combustion.

With the object above stated and others in View, as will appear when theinvention is more fully disclosed, the same consists in the constructionand combination of parts of a damper hereinafter described, illustratedin the accompanying' drawings, in which corresponding parts aredesignated by the same characters of reference, and having the novelfeatures thereof particularly pointed out in the appended claims.

In the drawings, Figure 1 is a View in vertical longitudinal sectionthrough the lire-box and the adjoining portions of a boiler, showing thedamper in closed position in association with the fire-box. Fig. 2 is adetail View in section through the back head of the lireboX, showing thedamper in open position. Fig. 3 is a view in section through the backhead of the fire-box, showing a modified. form of damper in closedposition.

Referring' to the drawings byreference characters, l designates the backhead7 or rear wall of the {ire-box of a locomotive.

2 2 designate the side bars upon which are supported the transversegrate-bars 3.

4 designates a brick arch disposed over the forward portion of thefire-box and set on an incline with the rear margin thereof above thefront margin, as shown. The arch l is supported in any suitable manner,as by inclined members 6. The line-sheet 7 is provided in front of thearch in the usual manner, and the lire-hox is provided at the rear witha door 8, covering an opening in the back head l.

` The rearmost one of the gratebars 3 is spaced from the back head l, asshown, leaving' an opening between the grate and the back head whichextends transversely across the entire fire-box between the side bars 2.Pivotally supported immediately below the opening between the rearmostgrate-bar and the back head is a dan1per-plate 9, I n'eferably supportedby trunnions 1l), at the ends thereof resting in bearing-slots 1l in theends of the side bars. l/Vhen the damper 9 is thus supported, thetrunnions l() are disposed intermediate of the front and rear edges ofthe damper-plate and nearer the rear margin, as shown. The damper-platcis of such width that when raised into horizontal position the rearwardmargin lies substantially in contact with the back head and the forwardmargin is under the rearmost grate-bar, so closing completely theopening' left at the rear of the grate.

Above the level of the grate and over the opening at the rear issupported a curved iron shield 12, the lower portion of which isinserted into a socket 13, provided in an upwardly-dsposed extension 14on each of the side bars 2. The shield lf2 lis provided with a pluralityof perforations l5 to permit the free passage of air, and itis curved atthe top so that the rear margin thereof rests against the back head 1.The shield l2 prevents the waste of coal by passing' downward throughthe opening' at the rear of the grate and also permits the passage intothe furnace of air allowed to pass upward through said opening when thedamper-plate is not in closed position.

A curved deiiector 16 is adjustably mounted above the shield l2 andextends over the upper portion thereof, as shown. The dellector 16 maybe shifted in position so as lto vary in height above the shield l2 fromthree to iive inches, so that the defiector may be brought into mosteffective position in relation to the shield and to the damper. Thepurpose of the guide-plate is to direct the air which passes upwardthrough the opening at the back of the grate when the damper is openforward and downward, so that it may not pass too soon up over the rearmargin of the brick arch and forward to the flue-sheet. The delectorprojects only a short distance beyond the shield, so as to permit thefireman to deposit coal just in front of said shield.

Movement is imparted to the damper-plate by means of a bentconnecting-rod pivoted at its forward end to a projection 17 on thelower surface of the damper-plate and pivoted at its rear end to one armof a bell-crank level' 18, supported by an eyebolt 19, which is attachedto the under side of the deck 2O of the engine-cab. From the other armof the bellcrank lever 18 extends upward an operatingrod 21, providedwith notches 22 in the side thereof to engage with a lug28 or othersuitable locking member and having at the top a suitable foot-piece Q4.By means of a slight pressure upon the top of the foot-piece 24 thefireman can disengage the rod 21 from the locking member and can shiftthe rod up and down until the desired adjustment of the damper-plate hasbeen effected. Then the damper-plate has been brought into suitableposition, the notch upon the rod 21, adapted to hold the damper-plate inproper position, will be brought into engagement with the pin 23 orother locking member, thus securing the damper-plate at the properinclination.

In the modified form of the invention (shown in Fig. 3) the damper-plate9a is hinged at l()a to the back head 1 and the other parts of thestructure are as already described.

In the operation of the damper mechanism above described thedamper-plate 9 is always adjusted by the rod 21, which extends upthrough the deck of the locomotive-cab on the firemans side. By means ofthis rod the fireman is enabled to set the damper instantly at anydesired inclination in relation to the plane of the grate-bars, so thatthe amount of air admitted may be accurately regulated to meet the needsof the fire. The damper-plate being pivoted near its rear margin andbeing arranged beneath the grate acts not only as means for controllingthe size of the opening at the rear of the grate through which air mayenter, but serves also as a deflector to direct upward through theopening at the rear of the grate the air which passes between the grateand the ash-pan. (Not shown.) Owing to the fact that the air whichpasses upward through the opening at the rear of the grate must firstpass rearward between the grate and the ash-pan below it,the air will bewarmed before it enters the fire-box, and itstendency to supportcombustion will be accordingly heightened. Furthermore, the fact thatthe air passes backward from the front of the ashpan, which is open,makes the pivoted damper-plate serve when the engine is in motion asmeans to produce a forced draft. The air which passes upward through theopening at the rear of the grate passes through openings in the shieldand either goes directly forward or is directed forward and downward bythe deflector mounted above the shield. The action of the deflectorcauses the air-currents passing through the shield to travel forwardbeyond the rear margin of the brick arch over the forward portion of thegrate to effect complete combustion of the smoke and combustible gasesin the fire-box before turning backward and rising over the rear marginof the brick arch in order to pass forward through the fire-tubes to thesmoke-stack at the front of the engine.

While I have described in the foregoing paragraphs and have illustratedin the accompanying drawings the preferred form of embodiment of theinvention, it is obvious that changes may be made in the form,proportions, and mode of assemblage of the elements without departingfrom the spirit of the invention or sacrificing any of its advantages.

Having thus described the nature and operation of my invention, what Iclaim as new, and desire to secure by Letters Patent, is-

1. The combination with the fire-box of a furnace, of a grateterminating a distance from one wall thereof for providing an openingthrough which air is forced from below the grate for intercepting thegases and products of combustion rising from the fire-bed, and means forbridging said opening to prevent the escape of fuel, comprising a curvedplate abutting at its upper longitudinal edge against the said wall ofthe fire-box, and having an engagement at its lower longitudinal edgewith the grate, said plate having orifices extending therethrough fordirecting air-currents close to the surface of the fire-bed andsubstantially parallel therewith, and other currents a distance abovethe first currents and at an angle thereto, substantially as described.

2. The combination with a fire-box, of a grate including cross-bars andside bars supporting the same and projecting' at one end beyond theoutermost cross-bar between which cross-bar and the adjacent walls ofthe fireboX an opening is provided through which air is forced frombelow the grate to intercept the gases and products of combustion risingfrom the fire-bed, a curved perforated plate bridging said openinghaving an engagement at its lower edge with said projecting portion ofthe side bars and supported thereby, and at its upper edge an engagementwith said wall of the fire-box, and a damper pivotally mounted atopposite ends in said side bars adjacent the outer ends of the same andhaving a swinging movement toward and away from the said wall of thefire-box, substantially as described.

3. The combination with a furnace, of a IOO IIO

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ire-bed having' an opening' at one margin thereof, a shield over saidopening', and a de- Hector-plate adjustably mounted above the shield todirect the current of air downward toward the lire-bed, substantiallyasdescribed.

1l. The combination with a furnace having a transverse opening' betweenthe lire-bed and the rear wall of the lire-box, of a damperplate beneathsaid opening, means for tilting plate having a similar curvature to saidshield disposed above said shield, and at a slight distance therefrom,substantially as described.

6. The combination with a furnace, of a fire-bed having' an opening atthe back thereof, a shield above said opening to preventthe escape offuel, a deiiector above the shield to direct air-currents downward andforward, an arch over the forward portion of the lire-bed to prevent thedirect passage of air-currents from the deflector to the lines leadingto the smole-staclr, and means beneath the opening' at the back of thefire-bed for forcing a current of air upward through said opening.

In testimony that I claim the foregoing as my own I have hereto ailixedmy signature .in the presence of two witnesses.

MICHAEL J. CARRIGAN.

Witnesses:

FRED SARS-ENT, EPHRAIM McDownLL.

